Charger system and method

ABSTRACT

Systems and methods of providing power through a Universal Serial Bus connector are provided. A charging system comprises an interface configured to receive power, a power converter coupled to the power source interface, the power converter configured to use the received power to generate power output, and a charging controller configured to control an amount of power provided at the USB connector on the power lines derived from the power output, and configured to generate an identification signal on the USB connector&#39;s two data lines, the identification signal usable to indicate the charger is not subject to standard USB power limitations, the identification signal provided through the use of a resistance between the D+ and D− data lines.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/892,709 filed Sep. 28, 2010 by Ryan M. Bayne, et al. entitled,“Charger System and Method”, which is a continuation of U.S. applicationSer. No. 12/496,042 filed Jul. 1, 2009 by Ryan M. Bayne, et al.entitled, “Charger System and Method” now U.S. Pat. No. 7,812,565 issuedon Oct. 12, 2010, which is a continuation of U.S. patent applicationSer. No. 11/749,676 filed May 16, 2007, now U.S. Pat. No. 7,573,242issued on Aug. 11, 2009, by Ryan M. Bayne, et al. entitled, “ChargerSystem and Method”, which is a continuation application of U.S.application Ser. No. 10/834,887 filed on Apr. 30, 2004, now U.S. Pat.No. 7,479,762, issued on Jan. 20, 2009, by Ryan M. Bayne, et al.entitled, “Charging Status Indicator Control System and Method”, whichis a filing under 35 U.S.C. 119 and claims priority to United KingdomPatent Application No. GB 0309942.1, filed Apr. 30, 2003, published asGB2401259 B, by Ryan M. Bayne et al., entitled “Charging StatusIndicator Control System and Method”, all of which are incorporated byreference herein as if reproduced in their entirety.

BACKGROUND

This invention relates generally to charging of devices havingrechargeable power supplies, and in particular to controlling chargingstatus indicators.

Many known charging systems for rechargeable power supplies areconfigured for connection to a device in which such a power supply isinstalled, so that the power supply need not be removed from the devicefor charging. Although charging systems often incorporate a chargingstatus indicator such as an LED, for example, devices are also typicallyequipped with power supply charge indicators to provide informationregarding remaining battery charge to a user. The user can then easilydetermine when a device power supply should be recharged.

When a device is connected to a charging system, however, the chargingstatus indicator on the charging system and the power supply chargeindicator may provide conflicting indications to a user. For example,different devices charged by the same charging system may have differentcharging current profiles, whereas charging status determination by thecharging system is based on a particular profile. In this case, thecharging system might either prematurely indicate that the power supplyin the device has been fully charged or continue to indicate that thepower supply is being charged after it has been fully charged. A correctindication of power supply charge at the device is then inconsistentwith the charging status indicator at the charging system, which mayconfuse a user.

SUMMARY

According to an aspect of the invention, a charging system comprises aninterface configured to receive power, a power converter coupled to thepower source interface, the power converter configured to use thereceived power to generate power output, and a charging controllerconfigured to control an amount of power provided at the USB connectoron the power lines derived from the power output, and configured togenerate an identification signal on the USB connector's two data lines,the identification signal usable to indicate the charger is not subjectto standard USB power limitations, the identification signal providedthrough the use of a resistance between the D+ and D− data lines.

In accordance with another aspect of the invention, a method forproviding a charge current by a charger having a Universal Serial Bus(“USB”) connector comprises the steps of receiving power at an interfaceconfigured to receive power, generating a power output derived from thereceived power and providing the generated power at the USB connector,and providing an identification signal using the USB connector's D+ andD− data lines, the identification signal usable to indicate the chargeris not subject to the standard USB power limitations, the identificationsignal provided through the use of a resistance between the D+ and D−data lines.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention identified in the claims may be more clearlyunderstood, preferred embodiments thereof will be described in detail byway of example, with reference to the accompanying drawings, in which:

FIG. 1 is a block diagram of a charging system having a charging statusindicator.

FIG. 2 is a block diagram of a charging system connected to a devicehaving a rechargeable power supply.

FIG. 3 is a schematic diagram of the Universal Serial Bus (USB)interface 28 of FIG. 2.

FIG. 4 is a flow diagram illustrating a charging status indicationcontrol method.

FIG. 5 is a block diagram of a wireless mobile communication device.

DETAILED DESCRIPTION

As described briefly above, devices having rechargeable power suppliesoften incorporate a power supply charge indicator, which might notalways be consistent with a charging status indicator in a chargingsystem used to charge the power supply. Depending on its type andresources, the device may be capable of controlling both its own powersupply charge indicator and the charging status indicator in thecharging system. For example, a device having a microprocessor, such asa personal digital assistant (“FDA”), a mobile communication device, acellular phone, a wireless two-way e-mail communication device, andother types of device, may have remote charging status indicationcontrol capabilities in conjunction with a suitably configured chargingsystem.

FIG. 1 is a block diagram of a charging system having a charging statusindicator. The charging system 10 includes a power source interface 12,a power converter 14, a charging controller 16, a charging statusindicator 17, and a device power and data interface 18. As indicatedbetween the charging controller 16 and the device power and datainterface 18, dashed lines indicate power transfer, while solid linesare used for data connections.

The power source interface 12 is configured for connection to a powersource from which rechargeable power supplies are charged. In oneembodiment, the power source interface 12 is a plug unit that can beused to couple with a conventional power socket to receive powertherefrom. For example, such a plug unit may be a two prong or threeprong plug of the type used in North America that can couple to a NorthAmerican AC power socket. Alternatively, the power source interface 12can accept one or more types of plug adapters configured to couple thepower source interface 12 to corresponding types of power sockets. Theuse of interchangeable plug adapters has the advantage of allowing thesame charging system to be used with a variety of types of power source,depending on availability. Thus, the power source interface 12 isconfigured to receive energy from a power source either directly orthrough the use of a plug adapter, and is operative to transfer thereceived energy to the power converter 14.

A power converter such as 14 typically includes at least one of thefollowing components: a switching converter, a transformer, a DC source,a voltage regulator, linear regulator, and a rectifier. The powerconverter 14 is operative to receive energy from a power source throughthe power source interface 12, and to convert that received energy to aform that can be used as a charging current to charge power supplies indevices connected to the charging system 10. For example, the powerconverter 14 can be of substantially conventional construction, such asa switching power converter that converts 115 VAC to 5 VDC. DC-to-DCconverters or DC regulators, which convert DC inputs to DC outputs arealso common in such power converters. In one embodiment, the powerconverter 14 is adapted to accept a wide range of input energy levelsand frequencies from the power source interface 12. Alternatively, thepower converter 14 is adapted to accept a limited range of input energylevels and frequencies, and the power source interface 12, or each plugadapter if any, is operable to convert the input energy levels andfrequencies into a range that the power converter 14 can accommodate.The power converter 14 provides its energy output to the chargingcontroller 16.

The charging controller 16 controls the amount of charging currentapplied to a device connected to the device power and data interface 18,and also controls the charging status indicator 17, as described infurther detail below. Although the charging controller 16 is preferablyimplemented in firmware, such as a microprocessor executing chargingcontrol software, those skilled in the art appreciate that hardwareimplementations of the charging controller 16 are also possible.

The charging status indicator 17 is typically an LED that is turned onby the charging controller 16 while the charging system 10 is charging arechargeable power supply and then turned off when charging is complete.The use of multiple LEDs in a charging status indicator such as 17 isalso known. For example, an LED of one color is turned on by thecharging controller 16 to indicate that a power supply is being charged,and when the power supply is charged to some predetermined level, an LEDhaving a different color is turned on. Sequential illumination ofmultiple LEDs is also used to provide an indication that a power supplyis being charged, and the current charge level. Other types of chargingstatus indicator, both LED-based and other types, will also be apparentto those skilled in the art. It should be appreciated that the presentinvention is in no way dependent upon any particular type of chargingstatus indicator 17.

The device power and data interface 18 is compatible with an interfaceprovided on a device having a power supply to be charged by the chargingsystem 10. Through the interface 18, charging current is supplied fromthe charging system 10 to the device and data is transferred from thedevice to the charging system. A single interface 18, such as a USBinterface, for example, that provides for transfer of both power anddata is generally preferable. However, separate power and datainterfaces may instead be provided as the power and data interface 18.

In operation, the charging controller 16 detects the connection of adevice having a rechargeable power supply to the device power and datainterface 18. In accordance with an aspect of the invention, thecharging controller 16 then determines whether the connected devicesupports remote control of the charging status indicator 17. Thisdetermination is based, for example, on an indicator control signalgenerated by the device and received by the charging controller 16. Ifthe interface 18 includes separate power and data interfaces, then thecharging controller 16 may detect the connection of the device to boththe power and data interfaces, and assume that a device connected toboth interfaces supports remote charging status indicator control. Thecharging controller 16 similarly determines that a device connected toonly the power interface does not support remote indicator control.

Responsive to a determination that the connected device does not supportremote control of the charging status indicator 17, the chargingcontroller 16 preferably provides charging current to the connecteddevice and controls the charging status indicator 17 in a conventionalfashion. Charging status is typically determined by measuring thecurrent drawn by a connected device, terminal voltage at the interface18, or some combination thereof. A “charging” indication is usuallyprovided as long as the measured current exceeds a predeterminedthreshold, whereas a “charged” indication is provided when the measuredcurrent drops below the threshold.

Where the connected device has the capability to remotely control thecharging status indicator 17, the charging controller 16 also providescharging current to the connected device, but controls the chargingstatus indicator 17 as directed by the connected device, instead of onthe basis of conventional current or voltage monitoring. In oneembodiment, an indicator control signal generated by the connecteddevice notifies the charging control system 16 that the connected devicesupports remote control of the charging status indicator 17. Thecharging control system then controls the charging status indicator 17to display a “charging” indication. Thereafter, the charging statusindicator 17 is controlled by the charging controller 16 as directed bythe connected device. When the connected device sends a charging statusupdate signal, to indicate that its power supply is charged, forexample, the charging controller 16 controls the charging statusindicator 17 to provide a “charged” indication. Control of both a devicepower supply charge indicator and the charging status indicator 17 bythe connected device provides consistent indications to a user. Althoughthe charging controller 16 may continue to monitor current and voltagefor other purposes, control of the charging status indicator 17 isdirected by the connected device. Disconnection of the device from thedevice power and data interface 18, or from the data interface whereseparate interfaces are provided, is preferably detected by the chargingcontroller 16, and the charging status indicator 17 is then eitherturned off, if the device is disconnected from both interfaces, orcontrolled in a conventional manner if a connection to a separate powerinterface is maintained.

Remote control of the charging status indicator 17 is either indirect,through the charging controller 16, or direct. Indirect control, byproviding control signals to the charging controller 16 instead ofdirectly to the charging indicator 17 is preferred in that drivers forthe charging status indicator 17 are not required at the device and nodata connection between the interface 18 and the charging statusindicator 17 is necessary. For a software- or firmware-based chargingcontroller 16, indirect control tends to be simpler. However, directcontrol of the charging status indicator 17 by the connected device isalso contemplated, particularly for a hardware-based charging controller16.

FIG. 2 is a block diagram of a charging system connected to a devicehaving a rechargeable power supply. In the charging system 20, thecomponents 22, 24, 26, 27, and 28 are substantially the same as thesimilarly-labeled components in FIG. 1, except that the device power anddata interface is a USB interface 27 in FIG. 2. The device 30, as shown,includes a USB interface 32 to the charging system 20, a powerdistribution and charging subsystem 34, a battery receptacle 36 forreceiving a rechargeable battery 38, a USB port 40, a microprocessor 42,and a battery charge indicator 43.

The battery 38 supplies power for the device 30 through the powerdistribution and charging subsystem 34. The power distribution andcharging subsystem 34 preferably uses the power provided by the chargingsystem 20 to both provide operating power to the device 30 and to chargethe battery 38. The particular design of the power distribution andcharging subsystem 34 is dependent upon the type of the device 30, aswill be apparent to those skilled in the art, and is substantiallyindependent of the charging status indicator control scheme describedherein. In the device 30, the power distribution and charging subsystem34 provides operating power to the microprocessor 42, the battery chargeindicator 43, and other device components. A data connection between themicroprocessor 42 and the power distribution and charging subsystem 34provides for software-based control and monitoring of the powerdistribution and charging subsystem 34. The microprocessor 42 alsodetermines a remaining charge level of the battery 38, by monitoring itterminal voltage, for example, and provides an indication of batterycharge to a user via the battery charge indicator 43. The battery chargeindicator 43 may include, for example, one or more LEDs or a userinterface (UI) component that displays an indication of battery chargelevel on a device display (not shown).

Another function of the microprocessor 42, in accordance with an aspectof the present invention, is to determine charging status of the battery38 when the device 30 is connected to the charging system 20. Asdescribed above, the power distribution and charging system 34preferably draws current from the charging system 20 to both charge thebattery 38 and provide operating power to the device 30. As such, thetotal amount of current drawn by the device 30 can be greater than anormal charging current for the battery 38 itself, and the device 30draws current after the battery 38 is fully charged. This may cause thecharging controller 26 to control the charging status indicator 26 toprovide a “charging” indication even though the battery 38 is no longerbeing charged. Varying charging current characteristics betweendifferent devices may also introduce errors in charging statusindication at the charging system 20. The microprocessor 42 or softwareexecuted by the microprocessor 42 is configured to determine actualcharging status of the battery 38, by measuring the charging currentbeing drawn by the battery 38 and comparing the measured current againstknown charging current profile for the device 30, for example, and tocontrol both the battery charge indicator 43 and the charging statusindicator 27 accordingly.

Operation of the charging system 20 is substantially as described above.When the device 30 is connected to the USB interface 28, the chargingcontroller 26 determines whether the device 30 supports remote controlof the charging status indicator 27. In one embodiment, thisdetermination is based on a predetermined potential or signal patternapplied to the USB connection between the USB interfaces 32 and 28 bythe device 30, as described in further detail below with reference toFIG. 3.

FIG. 3 is a schematic diagram of the USB interface 28 of FIG. 2. It willbe apparent to those skilled in the art that the Vbus line 44 and theGND line 50 carry power from the interface 28 to the interface 32, andthe D+ and D− data lines 46 and 48 provide the data connection. Theresistors 52 and 54, illustratively 7.5 kΩ and 15 k Ω, respectively,create a pull-up on the D− data line 48. In order to notify the chargingsystem 20 that it supports remote control of the charging statusindicator 27, the device 30 momentarily drives the D− data line 48 to alow level for a predetermined time when it is connected to the chargingsystem 20, and then allows it to return to a high level. Thesetransitions are detected by the charging controller 26 and interpretedas an indicator control signal, which serves to notify the chargingcontroller 26 that the device 30 supports remote control of the chargingstatus indicator 27. Charging status update signals are then provided tothe charging controller 26 to control the charging status indicator 27.

The number and types of charging status update signals provided to thecharging system 20 depend, for example, on the type of charging statusindicator 27 and the USB interface 28. In a preferred charging statusupdate signaling scheme, the device 30 pulls the D− line 48 to a lowlevel a second time to indicate that the battery 38 is fully charged. Ifthe charging status indicator 27 provides multi-level charging statusindications, then additional charging status update signals may beprovided to indicate a present charge level of the battery 38, chargingtime remaining, and the like. It is also possible to configure the USBinterface 28 to receive charging status update signals via the D+ and D−data lines 46 and 48.

The data connection between the USB interfaces 28 and 32 is shown inFIG. 2 as a one-way connection, with data flowing from the device 30 tothe charging system 20. However, a two-way data connection may also bedesirable, so that the device 30 can also detect that it has beenconnected to the charging system 20, for example. Typically, USB devicescan draw limited current from a USB host. In the case of a chargingsystem, such a limit may be undesirable. Therefore, when the device 30is connected to the USB interface 28, an identification signal ispreferably provided to the device 30 to notify the device 30 that it isconnected to a power source that is not subject to the normal powerlimits imposed by the USB specification. The identification signal alsopreferably causes the device 30 to provide an indicator control signalto the charging system 20.

An identification signal is provided, for example, by the chargingcontroller 26. In a more “passive” approach, USB interface 28 isconfigured to provide the identification signal. As described above, theresistors 52 and 54 create a slight pull-up on the D− data line 48.Although the resistor 56 creates a slight pull-down on the D+ data line46, D+ is pulled up by a stronger pull-up at the device 30 when it isconnected to the charger 20. Thus, in this embodiment, detection of theabnormal data line condition of both D− and D+ being high, in mostimplementations by the microprocessor 42, is interpreted as theidentification signal. The detection of the identification signal may beaccomplished using a variety of methods. For example, the microprocessor42 may detect the identification signal by detecting the presence of theabove or another abnormal data line condition at the USB port 40. Thedetection may also be accomplished through the use of other devicesubsystems in the device 30. Further details of USB-based charging areprovided in the following U.S. patent application Ser. Nos. 10/087,629,and 10/087,391, both filed on Mar. 1, 2002 and assigned to the owner ofthe instant application. The disclosure of each of these applications,including the specification and drawings thereof, is hereby incorporatedin its entirety herein by reference.

Referring again to FIG. 3, the resistor 56, connected between the D+data line 46 and the GND line 50, results in a pull-down on the D+ dataline 46. The stronger pull-up at the device 30 pulls D+ high when thedevice 30 is connected to the charging system 20. Connection of thedevice 30 to the charging system 20 can therefore be detected bydetecting that D+ has been pulled high. Other detection schemes may beapparent to those skilled in the art.

In response to the identification signal, the device 30 generates theindicator control signal and the power distribution and charging system34 draws power through Vbus and GND lines 44 and 50 of the USB interface28 without waiting for the normal USB processes of enumeration or chargenegotiation.

The USB connection between the device 30 and the charging system 20could be further exploited beyond charging the device 30. For example,the USB interface 32 may also be connected to other USB interfaces inother devices or systems, to support such extended functions asindirectly powering or charging power supplies in other devices andsystems through the device 30 through a conventional USB connection. Thedevice 30 then provides an interface to another device or power supplythat is not itself compatible with the charging system 20.

FIG. 4 is a flow diagram illustrating a charging status indicationcontrol method. The steps in the method have been described in detailabove and are therefore described briefly below.

As indicated at 70, a charging status indicator in a charging system isnormally turned off unless a device is connected to the charging system.Connection of a device having a rechargeable power supply is detected atstep 72. At step 74, a determination is made as to whether the connecteddevice supports remote control of the charging status indicator, basedon detection of an indicator control signal as described above, forexample. If so, then charging current is provided to the device, and thecharging status indicator provides a “charging” indication, at step 76.Steps 78 and 80 respectively illustrate monitoring for a charging statusupdate signal and disconnection of the device. In the example method ofFIG. 4, the “charging” indication is maintained until a charging statusupdate signal is received, as detected at step 78, or disconnection ofthe device is detected at step 80. When a charging status update signalindicating that the device power supply has been charged is received,charging is complete, and the charging status indicator is controlled toprovide a “charged” indication at step 82. Disconnection of the deviceturns the status indicator off, as shown at step 70.

Where it is determined at step 74 that the connected device does notsupport remote control of the charging status indicator, chargingcurrent is provided to the device and the charging status indicatorprovides a “charging” indication at step 84. The charging statusindicator is then controlled in a conventional manner, based on thecharging system determining when the device power supply has beencharged, at step 88, or that the device has been disconnected, at step86. Once the device power supply has been charged, charging is complete,and the charging status indicator provides a “charged” indication atstep 82.

The method shown in FIG. 4 and described above is one illustrativeexample of a charging status indicator control method. Modifications ofthe method are possible without departing from the invention.

For example, although only “charging” and “charged” indications areshown, the charging status control is also applicable to multiple-phasecharging cycles, including a constant current phase, a constant voltagephase, and a time-limited top-off charging phase, for example. A seriesof charging status update signals may be provided by a device anddetected by a charging system to indicate charging cycle status.Multiple charging status update signals are also preferred if a chargingstatus indicator can indicate power supply charge level or remainingcharging time during a charging operation. In other embodiments of theinvention, multiple charging status update signals are used to togglethe charging status indicator between “charged” and “charging”indications.

In addition, the method may revert to one of remote control andconventional control responsive to detection of certain conditions. If adevice's power supply is at a very low charge level, it may be unable topull down the D− data line when the device is connected to the chargingsystem to provide an indicator control signal as described above. Eventhough the device supports remote control of the charging statusindicator, it is unable to notify the charging system accordingly.However, after the power supply is partially charged, the device is ableto pull down the line to provide an indicator control signal. Where thecharging system is configured to monitor the D− data line after charginghas begun, a “late” indicator control signal can be detected, and themethod preferably reverts to remote indicator control. In the case ofseparate power and data interface, the method preferably reverts toconventional control if the device is disconnected from the datainterface.

Further, although the decision steps 78, 80, 86, and 88 are shown asseparate steps, it should be appreciated that these steps are preferablymonitoring operations that are performed during power supply charging.The charging at steps 76 and 84 need not be halted to check for acharging status update signal at step 78 or a power supply charge levelat step 88. Similarly, detection of disconnection of a device at steps80 and 86 interrupts the charging at steps 76 and 84, but the operationof detecting whether a device has been disconnected, such as by pollingan interface or monitoring for a detection signal, preferably does notrequire the charging to be halted.

FIG. 5 is a block diagram of a wireless mobile communication device,which is one type of device for which the charging status indicatorcontrol schemes disclosed herein are applicable. The wireless mobilecommunication device (“mobile device”) 100 is preferably a two-waycommunication device having at least voice or data communicationcapabilities. Preferably, the mobile device 100 is also capable ofcommunicating over the Internet, for example, via a radio frequency(“RF”) link.

The exemplary mobile device 100 comprises a microprocessor 112, acommunication subsystem 114, input/output (“I/O”) devices 116, a USBport 118, and a power subsystem 120. The microprocessor 112 controls theoverall operation of the mobile device 100. The communication subsystem114 provides the mobile device 100 with the ability to communicatewirelessly with external devices such as other mobile devices and othercomputers. The I/O devices 116 provide the mobile device 100 withinput/output capabilities for use with a device user. The USB port 118provides the mobile device 100 with a serial port for linking directlywith other computers and/or a means for receiving power from an externalpower source, as described above. The power subsystem 120 provides themobile device 100 with a local power source.

The communication subsystem 114 comprises a receiver 122, a transmitter124, antenna elements 126 and 128, local oscillators (LOs) 130, and adigital signal processor (DSP) 132. The particular design of thecommunication subsystem 114 and the components used therein can vary. Itwould be apparent to one of ordinary skill in the art to design anappropriate communication subsystem using conventional methods andcomponents to operate over a communication network 134 based on theparameters necessary to operate over that communication network. Forexample, a mobile device 100 geographically located in North America mayinclude a communication subsystem 114 designed to operate within theMobitex™ mobile communication system or DataTAC™ mobile communicationsystem, whereas a mobile device 100 intended for use in Europe mayincorporate a General Packet Radio Service (GPRS) communicationsubsystem 114.

Network access requirements will also vary depending upon the type ofnetwork 134. For example, in the Mobitex and DataTAC networks, mobiledevices 100 are registered on the network using a unique personalidentification number or PIN associated with each device. In GPRSnetworks however, network access is associated with a subscriber or userof a mobile device 100. A GPRS device therefore requires a subscriberidentity module (not shown), commonly referred to as a SIM card, inorder to operate on a GPRS network. Without a SIM card, a GPRS devicewill not be fully functional. Local or non-network communicationfunctions (if any) may be operable, but the mobile device 100 will beunable to carry out any functions involving communications over thenetwork 134, other than legally required functions such as ‘911’emergency calling.

When required, after the network registration or activation procedureshave been completed, a mobile device 100 may send and receivecommunication signals over the network 134. Signals received by theantenna element 126 are input to the receiver 122, which typicallyperforms such common receiver functions as signal amplification,frequency down conversion, filtering, channel selection, and in theexemplary system shown in FIG. 5, analog to digital conversion. Analogto digital conversion of a received signal allows more complexcommunication functions such as demodulation and decoding to beperformed in the DSP 132. Similarly, signals to be transmitted areprocessed, including modulation and encoding for example, by the DSP 132and input to the transmitter 124 for digital to analog conversion,frequency up conversion, filtering, amplification, and transmission overthe communication network 134 via the transmitter antenna element 128.The DSP 132 not only processes communication signals, but also providesfor receiver and transmitter control. For example, signal gains appliedto communication signals in the receiver 122 and transmitter 124 may beadaptively controlled through automatic gain control algorithmsimplemented in the DSP 132.

In implementing its device operation control function, themicroprocessor 112 executes an operating system. The operating systemsoftware used by the microprocessor 112 is preferably stored in apersistent store such as the non-volatile memory 136, or alternativelyread only memory (ROM) or similar storage element. The microprocessor112 may also enable the execution of specific device softwareapplications, such as a remote charging status indicator controlapplication or module, for example, which preferably are also stored ina persistent store. The operating system, specific device applications,or parts thereof, may also be temporarily loaded into a volatile storesuch as in RAM 138. The non-volatile memory 136 may be implemented, forexample, as a flash memory component, or a battery backed-up RAM, forexample.

A predetermined set of software applications which control basic deviceoperations, including at least data and voice communication applicationsfor example, will normally be installed on the mobile device 100 duringmanufacture. One such application loaded on the mobile device 100 couldbe a personal information manager (PIM) application. The PIM applicationis preferably a software application for organizing and managing userinputted data items such as e-mail, calendar events, voice mails,appointments, and task items. The PIM data items may be stored in theRAM 138 and/or the non-volatile memory 136.

The PIM application preferably has the ability to send and receive dataitems, via the wireless network 134. The PIM data items are preferablyseamlessly integrated, synchronized and updated, via the wirelessnetwork 134, with corresponding data items stored or associated with ahost computer system (not shown) used by the device user. Thesynchronization of PIM data items is a process by which the PIM dataitems on the mobile device 100 and the PIM data items on the hostcomputer system can be made to mirror each other.

There are several possible mechanisms for loading software applicationsonto the mobile device 100. For example, software applications may beloaded onto the mobile device 100 through the wireless network 134, anauxiliary I/O subsystem 140, the USB port 118, a short-rangecommunications subsystem 142, such as an infrared (“IR”), Bluetooth™, or802.11 communication system, or any other suitable subsystem 44. Thoseskilled in the art will appreciated that “Bluetooth” and “802.11” referto sets of specifications, available from the Institute for Electricaland Electronics Engineers (IEEE), relating to wireless personal areanetworks and wireless local area networks, respectively.

When loading software applications onto the mobile device 100, thedevice user may install the applications in the RAM 138 or thenon-volatile memory 136 for execution by the microprocessor 112. Theavailable application installation mechanisms can increase the utilityof the mobile device 100 by providing the device user with a way ofupgrading the mobile device 100 with additional and/or enhancedon-device functions, communication-related functions, or both. Forexample, a secure communication application may be loaded onto themobile device 100 that allows for electronic commerce functions or otherfinancial transactions to be performed using the mobile device 100.

The I/O devices 116 are used to accept inputs from and provide outputsto a user of the mobile device 100. In one mode of operation, a signalreceived by the mobile device 100, such as a text message or web pagedownload, is received and processed by the communication subsystem 114,forwarded to the microprocessor 112, which will preferably furtherprocess the received signal and provides the processed signal to one ormore of the I/O devices 116 such as the display 146. Alternatively, areceived signal such as a voice signal is provided to the speaker 148,or alternatively to an auxiliary I/O device 140. In another mode ofoperation, a device user composes a data item such as an e-mail messageusing a keyboard 150 in cooperation with the display 146 and/or possiblyan auxiliary I/O device 140. The composed data item may then betransmitted over a communication network 134 using the communicationsubsystem 114. Alternatively, a device user may compose a voice messagevia a microphone 152, or participate in a telephone call using themicrophone 152 and the speaker 148.

The short-range communications subsystem 142 allows the mobile device100 to communicate with other systems or devices, which need notnecessarily be similar to device 100. For example, the short-rangecommunications subsystem 142 may include an infrared device, a Bluetoothmodule, or an 802.11 module, as described above, to supportcommunications with similarly-enabled systems and devices.

The USB port 118 provides the mobile device 10 with a serial port forlinking directly with other computers to exchange data and/or to receivepower. The USB port 118 also provides the mobile device 100 with a meansfor receiving power from an external power source. For example, in apersonal digital assistant (PDA)-type communication device, the USB port118 could be used to allow the mobile device 100 to synchronize datawith a user's desktop computer (not shown). The USB port 118 could alsoenable a user to set parameters in the mobile device 100 such aspreferences through the use of an external device or softwareapplication. In addition, the USB port 118 provides a means fordownloading information or software to the mobile device 100 withoutusing the wireless communication network 134. The USB port 118 providesa direct and thus reliable and trusted connection that may, for example,be used to load an encryption key onto the mobile device 100 therebyenabling secure device communication.

Coupled to the USB port 118 is a USB interface 154. The USB interface154 is the physical component that couples the USB port to the outsideworld. In the exemplary mobile device 100, the USB interface 154 is usedto transmit and receive data from an external data/power source 156,receive power from the external data/power source 156, direct thetransmitted/received data from/to the USB port 118, and direct thereceived power to the power subsystem 120.

The power subsystem 120 comprises a charging and power distributionsubsystem 158 and a battery 160, which have been described above. Inconjunction with a charging system connected as the data/power source156, remote control of a charging status indicator by the mobile device100 in accordance with aspects of the present invention is supported.

This written description may enable those skilled in the art to make anduse embodiments having alternative elements that correspond to theelements of the invention recited in the claims. The intended scope ofthe invention thus includes other structures, systems or methods that donot differ from the literal language of the claims, and further includesother structures, systems or methods with insubstantial differences fromthe literal language of the claims.

For example, it would be obvious to implement remote charging statusindicator control in a charging system configured to simultaneouslycharge more than one device. In this case, separate charging statusindicators are typically provided, and each is controlled substantiallyindependently. At any time, each charging status indicator could becontrolled by either a connected device or the charging system. It isalso contemplated that such a charging system may incorporate more thanone type of device interface, including interfaces with both power anddata connections, through which remote charging status indicator controlis possible, and interfaces with only power connections, for whichcorresponding charging status indicators are controlled by the chargingsystem.

The USB connection shown in FIG. 2 is an illustrative example of onepossible type of power and data connection between a device and acharging system. Charging status indicator control as described hereinis not dependent upon any particular type of connection or interface,and is adaptable to other types of connections, associated withintegrated power/data interfaces or separate power and data interfaces.It will also be apparent that a data connection is not required wherepower connection signaling schemes are implemented. Where a device and acharging system are configured to detect particular potential or currentlevels on a power connection, a data connection is not necessary.

1. A charger configured to provide power through a Universal Serial Bus(USB) interface, the charger comprising: a power converter configured toreceive power from a power source and to generate a power output; and acharging controller configured to control an amount of power output fromthe charger, and to communicate an identification signal via USB datalines, the identification signal for indicating that the power outputexceeds standard USB power limits.
 2. The charger of claim 1, whereinthe data lines comprise a D+ line and a D− line, and the identificationsignal is based on a resistance between the D+ and D− data lines.
 3. Thecharger of claim 2, wherein the identification signal is based on thedata lines being pulled into a high state.
 4. The charger of claim 3,wherein the data lines are pulled into the high state using at least oneresistor.
 5. The charger of claim 1, further comprising at least oneUniversal Serial Bus connector coupled to the charging controller.
 6. Amethod for providing a charge current through a Universal Serial Bus(USB) connector, the USB connector comprising a D+ data line and a D−data line, the method comprising: receiving power at an interfaceconfigured to receive power from a power source; converting the receivedpower to a power output; delivering the power output to the USBconnector; and communicating an identification signal via the D+ and D−data lines, the identification signal for indicating that the poweroutput exceeds standard USB power limits.
 7. The method of claim 6wherein the identification signal is based on a resistance between theD+ and D− data lines.
 8. The method of claim 7, wherein theidentification signal comprises the data lines being pulled into a highstate.
 9. The method of claim 8, further comprising pulling the datalines into the high state using at least one resistor.
 10. The method ofclaim 6, further comprising a plurality of USB connectors, each USBconnector operable to provide the identification signal.
 11. A methodfor providing a charge current through a Universal Serial Bus (USB)connector, the USB connector comprising a D+ data line and a D− dataline, the method comprising: receiving power at an interface configuredto receive power from an external power source; converting the receivedpower to a power output; controlling an amount of power delivered to theUSB connector, the controlled amount of power derived from the poweroutput; enabling an identification signal on the D+ and D− data lines;and delivering output power to the USB connector based on at least oneof voltage and current draw detectable from power lines of the USBconnector, the output power not being limited by standard USB powerlimits.
 12. The method of claim 11, wherein the identification signalcomprises D+ and D− in a high logic state.
 13. The method of claim 12,wherein the data lines are pulled into a high state through resistance.14. The method of claim 13, further comprising pulling the data linesinto the high using at least one resistor.